TY - JOUR
T1 - Sensitivity of direct versus concentrated sputum smear microscopy in HIV-infected patients suspected of having pulmonary tuberculosis
AU - Cattamanchi, Adithya
AU - Dowdy, David W.
AU - Davis, J. Lucian
AU - Worodria, William
AU - Yoo, Samuel
AU - Joloba, Moses
AU - Matovu, John
AU - Hopewell, Philip C.
AU - Huang, Laurence
N1 - Funding Information:
This work was supported by grant numbers K24 HL087713 (LH), F32 HL088990 (JLD), and K23 AI080147 (JLD) from the National Institutes of Health, as well as an unrestricted grant from the Foundation for Innovative New Diagnostics.
PY - 2009/5/6
Y1 - 2009/5/6
N2 - Background: Sputum concentration increases the sensitivity of smear microscopy for the diagnosis of tuberculosis (TB), but few studies have investigated this method in human immunodeficiency virus (HIV)-infected individuals. Methods: We performed a prospective, blinded evaluation of direct and concentrated Ziehl-Neelsen smear microscopy on a single early-morning sputum sample in HIV-infected patients with > 2 weeks of cough hospitalized in Kampala, Uganda. Direct and concentrated smear results were compared with results of Lowenstein-Jensen culture. Results: Of 279 participants, 170 (61%) had culture-confirmed TB. The sensitivity of direct and concentrated smear microscopy was not significantly different (51% vs. 52%, difference 1%, 95% confidence interval (CI): [-7%, 10%], p = 0.88). However, when results of both direct and concentrated smears were considered together, sensitivity was significantly increased compared with either method alone (64%, 95% CI: [56%, 72%], p < 0.01 for both comparisons) and was similar to that of direct smear results from consecutive (spot and early-morning) specimens (64% vs. 63%, difference 1%, 95% CI: [-6%, 8%], p = 0.85). Among 109 patients with negative cultures, one had a positive direct smear and 12 had positive concentrated smears (specificity 99% vs. 89%, difference 10%, 95% CI: [2%, 18%], p = 0.003). Of these 13 patients, 5 (38%) had improved on TB therapy after two months. Conclusion: Sputum concentration did not increase the sensitivity of light microscopy for TB diagnosis in this HIV-infected population. Given the resource requirements for sputum concentration, additional studies using maximal blinding, high-quality direct microscopy, and a rigorous gold standard should be conducted before universally recommending this technique.
AB - Background: Sputum concentration increases the sensitivity of smear microscopy for the diagnosis of tuberculosis (TB), but few studies have investigated this method in human immunodeficiency virus (HIV)-infected individuals. Methods: We performed a prospective, blinded evaluation of direct and concentrated Ziehl-Neelsen smear microscopy on a single early-morning sputum sample in HIV-infected patients with > 2 weeks of cough hospitalized in Kampala, Uganda. Direct and concentrated smear results were compared with results of Lowenstein-Jensen culture. Results: Of 279 participants, 170 (61%) had culture-confirmed TB. The sensitivity of direct and concentrated smear microscopy was not significantly different (51% vs. 52%, difference 1%, 95% confidence interval (CI): [-7%, 10%], p = 0.88). However, when results of both direct and concentrated smears were considered together, sensitivity was significantly increased compared with either method alone (64%, 95% CI: [56%, 72%], p < 0.01 for both comparisons) and was similar to that of direct smear results from consecutive (spot and early-morning) specimens (64% vs. 63%, difference 1%, 95% CI: [-6%, 8%], p = 0.85). Among 109 patients with negative cultures, one had a positive direct smear and 12 had positive concentrated smears (specificity 99% vs. 89%, difference 10%, 95% CI: [2%, 18%], p = 0.003). Of these 13 patients, 5 (38%) had improved on TB therapy after two months. Conclusion: Sputum concentration did not increase the sensitivity of light microscopy for TB diagnosis in this HIV-infected population. Given the resource requirements for sputum concentration, additional studies using maximal blinding, high-quality direct microscopy, and a rigorous gold standard should be conducted before universally recommending this technique.
UR - http://www.scopus.com/inward/record.url?scp=67449158098&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67449158098&partnerID=8YFLogxK
U2 - 10.1186/1471-2334-9-53
DO - 10.1186/1471-2334-9-53
M3 - Article
C2 - 19419537
AN - SCOPUS:67449158098
SN - 1471-2334
VL - 9
JO - BMC infectious diseases
JF - BMC infectious diseases
M1 - 53
ER -